1. Field of the Invention
This invention relates to a bicycle wheel rim, more particularly to a bicycle wheel rim which has an enhanced resistance to buckling and which is capable of retaining spoke fasteners fittingly thereon.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional bicycle wheel rim 1 is shown to include spaced left and right tire retaining walls 12 and a spoke mounting wall 11 interconnecting inner edges of the tire retaining walls 12. The spoke mounting wall 11 is formed with a plurality of spoke fastening holes 10 that are slightly staggered and that are arranged generally along a central portion of the spoke mounting wall 11 for mounting of spoke fasteners 2 thereon (see FIGS. 2 and 3). A plurality of spokes 31 are fastened to the spoke fasteners 2 for mounting the bicycle wheel rim 1 on two opposite ends of a hub 3.
Some of the drawbacks of the conventional bicycle wheel rim 1 are as follows:
1. As shown in FIGS. 2 and 3, since the spoke fastening holes 10 are arranged along the central portion of the spoke mounting wall 11 with a distance (a) between adjacent pairs of the spoke fastening holes 10, the central portion of the spoke mounting wall 11 is susceptible to deformation due to the tension force applied thereto by the spokes 31 when the bicycle wheel rim 1 is in use.
2. As shown in FIG. 2, the spoke fastener 2 typically has a shank portion 20 and an enlarged head portion 21 with a tapering neck 212 connected to the shank portion 20. The spoke fastener 2 is loosely retained on the spoke mounting wall 11 since the spoke mounting wall 11 is not provided with retaining means for retaining fittingly the spoke fastener 2 thereon. This results in difficulties during assembly of the bicycle wheel rim 1 on the hub 3 to form a bicycle wheel.